The subject matter disclosed herein relates generally to wind turbines, and more specifically, to methods and apparatus for use in protecting wind turbine blades from lightning damage.
As is widely known, lightning may create a significant hazard to wind turbines. As such, at least some known wind turbines include protective equipment to facilitate preventing catastrophic damage to the wind turbines and/or wind turbine blades.
For example, in at least one known wind turbine, the wind turbine blades include metal wires or a metallic mesh to conduct electricity from the blades to the ground when struck by lightning. In such wind turbines, the blades are designed to provide an electrical path for the electricity to flow to ground in the event of a lightning strike, thus preventing damage to the blades and/or turbine.
Although such protective systems are frequently used, the effectiveness of such systems may be limited. For example, as electricity is routed to ground through such wind turbine, pressure within an associated turbine blade generated by the lightning strike may damage the blade if its pressure is too high. For example, when lightning strikes a turbine blade, current induced to the blade may cause an arc to form in the air inside the turbine blade. Such arcing may increase a temperature and/or pressure inside the blade. The resulting increase in temperature or pressure may cause cracks to develop in the blade, or may even explode the blade.
If a wind turbine blade is damaged due to lightning, repair of the blade may be costly and time-consuming. Moreover, damage to the blade may require a loss of electricity generation by the wind turbine (i.e. the wind turbine operation is ceased) until the blade is replaced or repaired.